The article aims to assess the G8 and G20 contribution towards development of global and regional mechanisms of collective governance and regulation. Analysis of these institutions’ effectiveness based on the functional paradigm enables to assess G8 and G20 contribution to the new mechanisms development by three groups of indicators: global governance functions implementation, including accountability and compliance with commitments; contribution to the key issues of global agenda and engagement with other international institutions. The analysis covers the period of G8 and G20 coexistence from 2008 to 2011. G8 documents issued from 1998 to 2008 were analyzed to compare its effectiveness before and after the start of the world economic crisis.

Thus, the study contributes to building a quantifiable evidence base for an assessment of the G8 and G20 effectiveness and enables to forecast their future roles in the development of collective regulation. On the basis of the G8 and G20 documents’ analysis the authors conclude that the trend for division of labour between G8, G20 and other international institutions will be essential for the institutions’ capacity to enhance the quality of collective governance.

The G20 made a substantial contribution into development of new forms of collective regulation in the priorities of economy, financial regulation and international financial system reform, while the role of G8 in these spheres of collective regulation diminished. However, the G8 continued to shape the global agenda in the spheres of political issues, security, international development cooperation, environment protection.

The G8 should not lower its capacity to interact with international institutions, including G20. The research shows that the G20 is following the multilateral approach which has got several advantages. First, it would increase G20’s legitimacy, second, the international partnerships would strengthen G20’s potential to develop new forms of regulation, third, it would help to implement the decisions made. Moreover, relevant international institutions ensure expert support to G20 activities, which is especially important given the complexity of such G20 priorities as financial regulation. Interaction with key international institutions could be also helpful for monitoring implementation of the decisions made.

The paper draws on the outcomes of the project «Analysis of developments in the global and regional mechanisms of collective governance and regulation» implemented within the Program of Fundamental Studies of Higher School of Economics in 2011.